Question

Tìm x

x(1-x)+x^2=3x+5

Answer 1

x( 1- x ) + x² = 3x + 5

<=> x - x² + x² - 3x - 5 = 0

<=> -2x - 5 = 0

<=> -2x = 5

<=> x = -5/2

Vậy....

Answer 2

\(x\left(1-x\right)+x^2=3x+5\)

\(\Leftrightarrow x-x^2+x^2-3x-5=0\)

\(\Leftrightarrow-2x-5=0\)

\(\Leftrightarrow-2x=5\)

\(\Leftrightarrow x=-\frac{5}{2}\)

Answer 3

x( 1- x ) + x^2 = 3x + 5

<=> x - x^2 + x^2 - 3x - 5 = 0

<=> -2x - 5 = 0

<=> -2x = 5

<=> x = -5/2

Answer 4

\(x\left(1-x\right)+x^2=3x+5\)

⇔ \(x-x^2+x^2-3x-5=0\)

⇔ \(-2x-5=0\)

⇔ \(-2x=0+5\)

⇔ \(-2x=5\)

⇔ \(x=5:\left(-2\right)\)

=> \(x=-\frac{5}{2}\)

Vậy \(x=-\frac{5}{2}\).

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